US4971625A - Method for leaching gold and/or silver out of ores or out of ore-concentrates and also out of precious-metal wastes or precious-metal scrap by using cyanide-containing leaching solutions - Google Patents
Method for leaching gold and/or silver out of ores or out of ore-concentrates and also out of precious-metal wastes or precious-metal scrap by using cyanide-containing leaching solutions Download PDFInfo
- Publication number
- US4971625A US4971625A US07/292,239 US29223988A US4971625A US 4971625 A US4971625 A US 4971625A US 29223988 A US29223988 A US 29223988A US 4971625 A US4971625 A US 4971625A
- Authority
- US
- United States
- Prior art keywords
- leaching
- flow
- solution
- slurry
- cyanide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 238000002386 leaching Methods 0.000 title claims abstract description 109
- XFXPMWWXUTWYJX-UHFFFAOYSA-N Cyanide Chemical compound N#[C-] XFXPMWWXUTWYJX-UHFFFAOYSA-N 0.000 title claims abstract description 32
- 239000010970 precious metal Substances 0.000 title claims abstract description 30
- 238000000034 method Methods 0.000 title claims abstract description 28
- 239000010931 gold Substances 0.000 title claims abstract description 20
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 title claims abstract description 19
- 229910052737 gold Inorganic materials 0.000 title claims abstract description 19
- 229910052709 silver Inorganic materials 0.000 title claims abstract description 7
- 239000004332 silver Substances 0.000 title claims abstract description 7
- 239000012141 concentrate Substances 0.000 title claims description 5
- 239000002699 waste material Substances 0.000 title claims description 3
- 239000002002 slurry Substances 0.000 claims abstract description 78
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims abstract description 22
- 239000000126 substance Substances 0.000 claims abstract description 11
- 239000000243 solution Substances 0.000 claims description 41
- MNWBNISUBARLIT-UHFFFAOYSA-N sodium cyanide Chemical compound [Na+].N#[C-] MNWBNISUBARLIT-UHFFFAOYSA-N 0.000 claims description 31
- 239000010949 copper Substances 0.000 claims description 9
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 7
- 229910052802 copper Inorganic materials 0.000 claims description 7
- 239000007864 aqueous solution Substances 0.000 claims description 6
- 229960002163 hydrogen peroxide Drugs 0.000 claims description 6
- 229920002134 Carboxymethyl cellulose Polymers 0.000 claims description 5
- 229920006318 anionic polymer Polymers 0.000 claims description 5
- 239000001768 carboxy methyl cellulose Substances 0.000 claims description 5
- 235000010948 carboxy methyl cellulose Nutrition 0.000 claims description 5
- 239000008112 carboxymethyl-cellulose Substances 0.000 claims description 5
- 239000003352 sequestering agent Substances 0.000 claims description 5
- 229910052742 iron Inorganic materials 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 4
- 150000002978 peroxides Chemical class 0.000 claims description 4
- 239000003795 chemical substances by application Substances 0.000 claims description 3
- 229920002472 Starch Polymers 0.000 claims description 2
- RYYWUUFWQRZTIU-UHFFFAOYSA-N Thiophosphoric acid Chemical class OP(O)(S)=O RYYWUUFWQRZTIU-UHFFFAOYSA-N 0.000 claims description 2
- 235000019698 starch Nutrition 0.000 claims description 2
- 150000003558 thiocarbamic acid derivatives Chemical class 0.000 claims description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 claims 1
- 239000008107 starch Substances 0.000 claims 1
- 238000000354 decomposition reaction Methods 0.000 description 9
- 238000000605 extraction Methods 0.000 description 9
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 8
- 239000001301 oxygen Substances 0.000 description 8
- 229910052760 oxygen Inorganic materials 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 7
- 238000012360 testing method Methods 0.000 description 5
- 239000003153 chemical reaction reagent Substances 0.000 description 4
- 239000006185 dispersion Substances 0.000 description 3
- 230000014759 maintenance of location Effects 0.000 description 3
- 239000012989 trithiocarbonate Substances 0.000 description 3
- HIZCIEIDIFGZSS-UHFFFAOYSA-L trithiocarbonate Chemical compound [S-]C([S-])=S HIZCIEIDIFGZSS-UHFFFAOYSA-L 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 2
- MBMLMWLHJBBADN-UHFFFAOYSA-N Ferrous sulfide Chemical compound [Fe]=S MBMLMWLHJBBADN-UHFFFAOYSA-N 0.000 description 2
- 235000011941 Tilia x europaea Nutrition 0.000 description 2
- 239000000920 calcium hydroxide Substances 0.000 description 2
- 235000011116 calcium hydroxide Nutrition 0.000 description 2
- 238000005188 flotation Methods 0.000 description 2
- LELOWRISYMNNSU-UHFFFAOYSA-N hydrogen cyanide Chemical compound N#C LELOWRISYMNNSU-UHFFFAOYSA-N 0.000 description 2
- 239000004571 lime Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 108091005950 Azurite Proteins 0.000 description 1
- -1 Fe(III) ions Chemical class 0.000 description 1
- 101100386054 Saccharomyces cerevisiae (strain ATCC 204508 / S288c) CYS3 gene Proteins 0.000 description 1
- 241000907663 Siproeta stelenes Species 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000001252 acrylic acid derivatives Chemical class 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 239000003610 charcoal Substances 0.000 description 1
- KXZJHVJKXJLBKO-UHFFFAOYSA-N chembl1408157 Chemical compound N=1C2=CC=CC=C2C(C(=O)O)=CC=1C1=CC=C(O)C=C1 KXZJHVJKXJLBKO-UHFFFAOYSA-N 0.000 description 1
- 230000000536 complexating effect Effects 0.000 description 1
- 239000008139 complexing agent Substances 0.000 description 1
- 229910001779 copper mineral Inorganic materials 0.000 description 1
- XLJMAIOERFSOGZ-UHFFFAOYSA-M cyanate Chemical compound [O-]C#N XLJMAIOERFSOGZ-UHFFFAOYSA-M 0.000 description 1
- 238000007883 cyanide addition reaction Methods 0.000 description 1
- 238000001784 detoxification Methods 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 239000007970 homogeneous dispersion Substances 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 229910001608 iron mineral Inorganic materials 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 150000002825 nitriles Chemical class 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 229910052683 pyrite Inorganic materials 0.000 description 1
- NIFIFKQPDTWWGU-UHFFFAOYSA-N pyrite Chemical compound [Fe+2].[S-][S-] NIFIFKQPDTWWGU-UHFFFAOYSA-N 0.000 description 1
- 239000011028 pyrite Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 230000002269 spontaneous effect Effects 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 101150035983 str1 gene Proteins 0.000 description 1
- 229910052569 sulfide mineral Inorganic materials 0.000 description 1
- 150000004763 sulfides Chemical class 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- GWBUNZLLLLDXMD-UHFFFAOYSA-H tricopper;dicarbonate;dihydroxide Chemical compound [OH-].[OH-].[Cu+2].[Cu+2].[Cu+2].[O-]C([O-])=O.[O-]C([O-])=O GWBUNZLLLLDXMD-UHFFFAOYSA-H 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B11/00—Obtaining noble metals
- C22B11/08—Obtaining noble metals by cyaniding
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Definitions
- the invention relates to a method for recovering precious metal components by leaching gold and/or silver out of ores or ore-concentrates and also out of precious-metal wastes or precious-metal scrap.
- Method for recovery of the precious metal values employs cyanide-containing leaching solutions having a pH value between 7 and 13 by adding an aqueous H 2 O 2 solution.
- the starting material is finely ground and dispersed in water to form a slurry.
- the pH value of the ore slurry is then raised into the alkaline pH range by adding lime or milk of lime, whereupon the complexforming cyanide is added, as a rule in the form of NaCN in an aqueous solution of approximately 5 to 20%.
- the ore slurry is agitated, with introduction of air, for 24 to 48 hours in stirring tanks or Pachuca tanks for a time period of 24 to 48 hours.
- the pH value of the ore slurry must be raised into the alkaline range and be kept there. Ordinarily, the process takes place in the pH range from 10 to 11. Typically, this pH range is set by adding lime and milk of lime in the ratio of 80:20.
- the cyanide concentration of the ore slurry depending on the ore composition ranges from 0.025 to 0.25 % by weight of NaCN.
- the cyanide is metered in the form of an aqueous solution of 2 to 20 % into the first of up to ten cascaded leaching tanks traversed by the slurry.
- a concentration of dissolved oxygen in the slurry is chosen to be as close as possible to the physically determined maximum value of about 8 to 9 ppm because at the practicable conventional cyanide concentration of 0.3 to 3 kg/ton of ore, the diffusion of the dissolved oxygen in the slurry determines the rate of leaching.
- KCN also may be used just as well.
- the molar ratio of NaCN/H 2 O 2 set in the above known procedure indicates that operation takes place at a pH value between 9.5 and 11.5 as in the previously described detoxification of the leaching slurries. Because of the marked decomposition of the NaCN in its reaction with the added H 2 O 2 only that NaCN added in excess is available for complexing the precious metals.
- German patent 36 37 082 describes a procedure for the leaching of gold and/or silver out of ores or oreconcentrates employing an aqueous cyanide leaching solution with a pH of 8 to 13 and adding an aqueous solution of H 2 O 2 .
- this prior process is carried out by controlling the addition of said H 2 O 2 solution by means of the concentration of the oxygen dissolved in the leaching solution, the oxygen content in said solution being set at 2 to 20 mg/liter.
- the purpose thereof is to carry out the leaching more 0 economically, in particular by reducing the H 2 O 2 consumption, without thereby entailing higher sodium cyanide consumption relative to the previously known leaching with air blowing.
- the object of the invention is to provide an improved leaching process and to appreciably shorten the leaching time relative to the known procedure while operating at the conventional NaCN concentration in the leaching slurry and with low consumption of H 2 O 2 , whereby also the costs of carrying out the method shall be significantly lowered.
- the invention is based on the discovery that the reaction between NaCN and H 2 O 2 is strongly inhibited, that is it takes place more slowly in the alkaline pH range below 10 or above 11 and up to 13.
- the NaCN is maintained as a complexing agent while simultaneously the desired concentration of dissolved oxygen in the slurry is obtained by the decomposition of the H 2 O 2 as required for the reaction between the NaCN and the precious metal as explained initially above.
- an optimal ratio of H 2 O 2 concentration to the amount of precious metal to be leached and to the NaCN concentration is achieved over the entire leaching time.
- the leaching slurry contains the highest amounts of precious metals to be leached and the highest amounts of cyanide.
- the contents in H 2 O 2 in the leaching slurry automatically adjust themselves to the lessened demand.
- the hydrogen-peroxide solution In order to accelerate the leaching process, it is necessary that as soon as the H 2 O 2 solution is introduced, it be homogeneously dispersed in the leaching slurry because otherwise local detrimental molar ratios NaCN/H 2 O 2 will occur in this leaching slurry which would result in accelerated decomposition of the NaCN whereby either the output of precious metals would be lowered or the necessary addition of NaCN would be increased. Accordingly, it is advantageous for the hydrogen-peroxide solution to be added continuously and homogeneously dispersed across the cross-section of a flow of leaching slurry.
- the H 2 O 2 solution can be added to the leaching slurry both before or after the cyanide is added.
- the addition of the H 2 O 2 solution is added before the cyanide is introduced into the leaching slurry because thereby an O 2 enrichment and dispersion in the slurry can be achieved before the cyanide addition.
- the NaCN concentration is about 0.25 to 1 g per liter of the leaching slurry. It was ascertained by a series of tests that when liter of leaching slurry at a pH of 9, almost 100% of the precious metals can be extracted from this slurry after about 100 minutes. The precious metals can be separated in problem-free manner by charcoal adsorption.
- the new method reduces the time for leaching precious metals to 1/5 to 1/20 of the times needed by the conventional procedures of the state of the art. Instead of the previous leaching times of 24 to 48 hours times of 2 to 4 hours are sufficient when using the new method.
- the amount of the added H 2 O 2 solution is not limited by the quantity of NaCN present in the leaching slurry. Rather the H 2 O 2 amount may be clearly higher than that required for complete decomposition of the NaCN, without having to incur an undesired decomposition of the NaCN. Practice has shown it is advantageous to add the H 2 O 2 solution in such a quantity that the amount of the H 2 O 2 is 0.1 to 2.5 kg per ton of ore, for typical cyanide concentrations of 0.1 to 3 kg of NaCN per ton of ore.
- An advantageous mode of introduction of the H 2 O 2 solution into the flow of leaching slurry is carried out by feeding the H 2 O 2 solution crosswise to this flow of leaching slurry at 10 to 50 times the flow rate of the flow of leaching slurry.
- a preferred mode of implementation is characterized in that the leaching slurry is guided at a rate of 1 to 3 meters/sec. in the feed region of the H 2 O 2 solution and, further, in that the cross-flow of the H 2 O 2 solution is set for a rate of 10 to 100 meters/sec.
- the feed of the H 2 O 2 solution into the flow of leaching slurry is carried out by conventional feed devices, preferably by slit-nozzles dimensioned in the micron range.
- uniform dispersion of the H 2 O 2 into the flow of the leaching slurry is achieved within fractions of a second.
- slit apertures of 5 to 100 microns are recommended if the H 2 O 2 solution is added to the leaching slurry in the area of tubular cross-section having a diameter no larger than 10 cm.
- flotation reagents or anionic polymers in amounts of 5 to 1,000 g per ton of ore, preferably 25 to 250 g per ton, to the leaching slurry, in order to passivate or sequester the copper or iron minerals.
- the addition of the flotation reagents or polymers takes place after the pH has been set in the leaching slurry, or before the H 2 O 2 solution and the cyanide are added.
- Preferred sequestering or passivating agents are thiocarbonates, thiophosphates, thiocarbamates or anionic polymers in the form of acrylates, starches, and carboxymethyl cellulose.
- the passivating or sequestering agents as a rule are added in the form of a 0.1 to 10 % by weight aqueous solution to the leaching slurry. Any suitable agent of this type can be used for purposes of the invention.
- reagents as described herein advantageously should also take place in homogeneously dispersed manner over the cross-section of the slurry flow.
- aqueous solutions this can be carried out using slit-nozzles, as already discussed in relation to the feed of the H 2 O 2 .solution
- the homogeneous or short-term dispersion of the passivating of sequestering agents results in shortening their reaction times with Cu or Fe minerals respectively.
- a gold ore rich in malachite/azurite (this is the leaching residue of a shut down gold-processing plant) contains about 3 ppm gold and 1.2 % copper as an important accompanying element.
- the gold ore is ground to a d 80 value of 200 microns.
- the ore is leached at a slurry density of 500 g of ore per liter of leach while being agitated with turbulence and with addition of NaCN between 0.02 to 0.2 % by weight.
- the pH values of the leaching slurries are varied between 9 and 12.
- H 2 O 2 solution 0.6 ml of 35% H 2 O 2 solution per liter of leach is fed through slit-nozzles, before the introduction of the NaCN, to the ore slurry having a density of 500 g of ore per liter of leach. This is carried out in such a way that a NaCN concentration of the leach of 0.05 % by weight is obtained.
- the H 2 O 2 concentration of the leach is 0.02 % by weight.
- the ore ground to a d 80 value of 200 microns is reacted at a slurry density of 500 g of ore per liter of leach with 0.7 kg NaCN per ton of ore and is aerated by air being blown in.
- the slurry pH was set at 11.
- the slurry of (C) with the same amount of NaCN and after its pH value has been set to 9 receives the peroxide solution until the amount of H 2 O 2 per ton of ore is 1.6 kg.
- the slurry density was 500 g of ore per liter of leach and the addition of NaCN was 0.8 kg per ton of ore.
- the H 2 O 2 solution was added until 1 kg of H 2 O 2 was present per ton of ore.
- the Table shows that absent passivating sequestering the copper and iron sulfide, only a gold extraction of a maximum of 68 % is possible at a slurry pH of 11 and only of 55 % at a slurry pH of 9, and that further addition of H 2 O 2 takes place, whereas an increase in extraction is achieved already after leaching for 3 h up to 97% when adding the said passivating sequestering reagents.
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacture And Refinement Of Metals (AREA)
Abstract
Description
______________________________________ pH 9 pH 9 pH 9 pH 2.88 pH 9 H.sub.2 O.sub.2 H.sub.2 O.sub.2 H.sub.2 O.sub.2 Au extraction air H.sub.2 O.sub.2 AX CMC TTC ______________________________________ after 3 h. 25% 55% 90% 92% >97% after 24 h. 68% 58% 91% 93% >97% ______________________________________
Claims (4)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE3801741A DE3801741C1 (en) | 1988-01-22 | 1988-01-22 | |
DE3801741 | 1988-01-22 |
Publications (1)
Publication Number | Publication Date |
---|---|
US4971625A true US4971625A (en) | 1990-11-20 |
Family
ID=6345747
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US07/292,239 Expired - Fee Related US4971625A (en) | 1988-01-22 | 1988-12-30 | Method for leaching gold and/or silver out of ores or out of ore-concentrates and also out of precious-metal wastes or precious-metal scrap by using cyanide-containing leaching solutions |
Country Status (9)
Country | Link |
---|---|
US (1) | US4971625A (en) |
EP (1) | EP0327695B1 (en) |
AR (1) | AR240176A1 (en) |
AU (1) | AU604389B2 (en) |
BR (1) | BR8900199A (en) |
DE (1) | DE3801741C1 (en) |
NZ (1) | NZ227675A (en) |
PH (1) | PH26633A (en) |
ZA (1) | ZA89137B (en) |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AU633203B2 (en) * | 1990-06-02 | 1993-01-21 | Degussa A.G. | A process for leaching gold and silver |
US5215575A (en) * | 1989-03-07 | 1993-06-01 | Butler Dean R | Recovery of gold, silver and platinum group metals with various leachants at low pulp densities |
US5250272A (en) * | 1988-09-09 | 1993-10-05 | Degussa Aktiengesellschaft | Process for leaching precious metals with hydrogen-peroxide and a cyanide leaching solution |
US5275791A (en) * | 1986-10-31 | 1994-01-04 | Degussa Aktiengesellschaft | Process for the leaching of gold and silver with cyanidic leaching solution and controlled addition of hydrogen peroxide |
US5336474A (en) * | 1990-06-02 | 1994-08-09 | Degussa Aktiengesellschaft | Process for leaching of precious metals |
US5368830A (en) * | 1992-10-15 | 1994-11-29 | Calgon Corporation | Scale control in gold and silver mining heap leach and mill water circuits using polyether polyamino methylene phosphonates |
AU656899B2 (en) * | 1990-08-16 | 1995-02-23 | University Of The Witwatersrand | Determining cyanide concentration |
WO1997044793A1 (en) * | 1996-05-21 | 1997-11-27 | British Nuclear Fuels Plc | Decontamination of metal |
US5961833A (en) * | 1997-06-09 | 1999-10-05 | Hw Process Technologies, Inc. | Method for separating and isolating gold from copper in a gold processing system |
ES2163948A1 (en) * | 1998-07-14 | 2002-02-01 | Consejo Superior Investigacion | Hydrometallurgical procedure for retrieving gold from mineral and metallic materials. |
US6355175B1 (en) | 1997-06-09 | 2002-03-12 | Hw Process Technologies, Inc. | Method for separating and isolating precious metals from non precious metals dissolved in solutions |
US6406675B1 (en) * | 2000-09-13 | 2002-06-18 | Hercules Incorporated | Method for reducing cyanide consumption during processing of gold and silver ores to remove base metals |
US20050067341A1 (en) * | 2003-09-25 | 2005-03-31 | Green Dennis H. | Continuous production membrane water treatment plant and method for operating same |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CA2051698C (en) * | 1989-04-28 | 1997-12-30 | Trevor John Smith | Recovery of gold and silver from complex refractory sulphide ores by cyanidisation and oxidation with peroxides |
WO1990013676A1 (en) * | 1989-04-28 | 1990-11-15 | Cra Services Limited | Recovery of gold and silver from complex refractory sulphide ores by cyanidisation and oxidation with peroxides |
ES2038535B1 (en) * | 1991-06-14 | 1994-04-01 | Riotinto Minera Sa | PROCEDURE FOR THE HYDROMETALLURGICAL RECOVERY OF NON-IRON METALS IN ASHES OF PIRITAS. |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US732605A (en) * | 1902-11-18 | 1903-06-30 | Gustav E Thede | Process of leaching ores. |
US3203968A (en) * | 1959-06-03 | 1965-08-31 | Sebba Felix | Ion flotation method |
US3339730A (en) * | 1962-07-14 | 1967-09-05 | Column Flotation Co Of Canada | Froth flotation method with counter-current separation |
US3826723A (en) * | 1972-07-13 | 1974-07-30 | Elmet Inc | Process for recovering gold and silver |
US4421724A (en) * | 1981-09-08 | 1983-12-20 | Anglo Mineral Resources, Inc. | Extraction method for refractory precious metal ore |
CA1221842A (en) * | 1983-06-03 | 1987-05-19 | Arthur E. Coburn | Treatment of ores |
US4786318A (en) * | 1986-08-14 | 1988-11-22 | Nalco Chemical Company | Thickening of gold process slurries |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3637082C1 (en) * | 1986-10-31 | 1988-05-19 | Degussa | Process for leaching precious metals from ores or ore concentrates using cyanide solutions with the addition of hydrogen peroxide |
-
1988
- 1988-01-22 DE DE3801741A patent/DE3801741C1/de not_active Expired
- 1988-12-01 EP EP88120042A patent/EP0327695B1/en not_active Expired - Lifetime
- 1988-12-12 AU AU26797/88A patent/AU604389B2/en not_active Withdrawn - After Issue
- 1988-12-30 US US07/292,239 patent/US4971625A/en not_active Expired - Fee Related
-
1989
- 1989-01-06 ZA ZA89137A patent/ZA89137B/en unknown
- 1989-01-18 BR BR898900199A patent/BR8900199A/en unknown
- 1989-01-18 AR AR313016A patent/AR240176A1/en active
- 1989-01-20 NZ NZ227675A patent/NZ227675A/en unknown
- 1989-01-20 PH PH38080A patent/PH26633A/en unknown
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US732605A (en) * | 1902-11-18 | 1903-06-30 | Gustav E Thede | Process of leaching ores. |
US3203968A (en) * | 1959-06-03 | 1965-08-31 | Sebba Felix | Ion flotation method |
US3339730A (en) * | 1962-07-14 | 1967-09-05 | Column Flotation Co Of Canada | Froth flotation method with counter-current separation |
US3826723A (en) * | 1972-07-13 | 1974-07-30 | Elmet Inc | Process for recovering gold and silver |
US4421724A (en) * | 1981-09-08 | 1983-12-20 | Anglo Mineral Resources, Inc. | Extraction method for refractory precious metal ore |
CA1221842A (en) * | 1983-06-03 | 1987-05-19 | Arthur E. Coburn | Treatment of ores |
US4786318A (en) * | 1986-08-14 | 1988-11-22 | Nalco Chemical Company | Thickening of gold process slurries |
Non-Patent Citations (4)
Title |
---|
Davidson, R. J. et al. "The Intensive Cyandation of Gold-Plant Gravity Concentrates", J. of S. African Inst. of Min. and Met., Jan. 1978 pp. 146-165. |
Davidson, R. J. et al. The Intensive Cyandation of Gold Plant Gravity Concentrates , J. of S. African Inst. of Min. and Met., Jan. 1978 pp. 146 165. * |
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Also Published As
Publication number | Publication date |
---|---|
ZA89137B (en) | 1989-10-25 |
EP0327695A1 (en) | 1989-08-16 |
AR240176A1 (en) | 1990-02-28 |
EP0327695B1 (en) | 1992-07-01 |
NZ227675A (en) | 1990-04-26 |
AU604389B2 (en) | 1990-12-13 |
PH26633A (en) | 1992-09-04 |
DE3801741C1 (en) | 1989-06-15 |
BR8900199A (en) | 1989-09-12 |
AU2679788A (en) | 1989-07-27 |
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